Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 40b231f3220b548e…

MALICIOUS

Office (OLE)

35.5 KB Created: 2020-11-25 10:44:16 Authoring application: Microsoft Excel First seen: 2021-06-17
MD5: d7b5a22e40a60b39ab0dd5d15d8d86a4 SHA-1: 2fb897cac58e9eda65e77c587f136fcfc89260a9 SHA-256: 40b231f3220b548e36160e85da9edfac433b91c462d23a1ff34191036f39b896
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1203 Exploitation for Client Execution

The sample is an Excel file containing Excel 4.0 macros, specifically an Auto_Open defined name. This indicates the macros will run automatically when the workbook is opened. The presence of dangerous formula APIs like RUN suggests the macro's intent is to execute arbitrary code, likely downloading and running a second-stage payload. No specific family could be identified.

Heuristics 3

  • Excel 4.0 Auto_Open defined name critical OLE_XLM_AUTOOPEN_DEFINEDNAME
    oletools recovered an Auto_Open / Auto_Close entry from an Excel 4.0 macro sheet. The raw BIFF name can be tokenized or partially opaque to byte-string checks, but the recovered macro listing confirms the workbook has an XLM auto-execution entry.
  • XLM Auto_Open with dangerous formula APIs critical OLE_XLM_DANGEROUS_FN
    Excel 4.0 macro sheet contains an Auto_Open / Auto_Close entry and dangerous XLM formula APIs that can invoke programs, write files, or transfer control without VBA.
  • Excel 4.0 (XLM) macro sheet present medium OLE_XLM_AUTOOPEN
    Workbook contains an Excel 4.0 macro sheet sub-stream — XLM is rarely seen in modern legitimate workbooks and was a major Office malware vector during 2020-2022.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6377 bytes
SHA-256: aa2f41551b9f9dd2734cf0b227d999d61e344a49ad4b562d2baad57a7b434525
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     14 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  LcQUv
' 0018     21 LABEL : Cell Value, String Constant - ACtYfV len=0 
' 0018     23 LABEL : Cell Value, String Constant - aUMHrkbL len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!G165 
' 0018     20 LABEL : Cell Value, String Constant - BNUzi len=0 
' 0018     20 LABEL : Cell Value, String Constant - Cmvwp len=0 
' 0018     26 LABEL : Cell Value, String Constant - dTRcsnYkbht len=0 
' 0018     26 LABEL : Cell Value, String Constant - erVMvheKciX len=0 
' 0018     24 LABEL : Cell Value, String Constant - GhXltZgYK len=0 
' 0018     21 LABEL : Cell Value, String Constant - hZUHTv len=0 
' 0018     20 LABEL : Cell Value, String Constant - IoyPr len=0 
' 0018     26 LABEL : Cell Value, String Constant - keTYVGMVifN len=0 
' 0018     20 LABEL : Cell Value, String Constant - KNgzT len=0 
' 0018     25 LABEL : Cell Value, String Constant - kPqxmcrOnM len=0 
' 0018     21 LABEL : Cell Value, String Constant - OraykA len=0 
' 0018     25 LABEL : Cell Value, String Constant - PSZMOoznDa len=0 
' 0018     20 LABEL : Cell Value, String Constant - VIzlq len=0 
' 0018     24 LABEL : Cell Value, String Constant - WTOjUHDac len=0 
' 0018     22 LABEL : Cell Value, String Constant - xijpoEG len=0 
' 0018     26 LABEL : Cell Value, String Constant - xOhLLPaVsQq len=0 
' 0018     21 LABEL : Cell Value, String Constant - yarRli len=0 
' 0018     20 LABEL : Cell Value, String Constant - yeREG len=0 
' 002a      2 PRINTHEADERS : Print Row/Column Labels
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell 
... (truncated)

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